Unbound < 1.4.4 Unbound Signed Zone Query Response DNSSEC Outage DoS

medium Nessus Plugin ID 55048


The remote name server is affected by a denial of service vulnerability.


According to its self-reported version number, the remote Unbound DNS resolver is affected by a denial of service vulnerability due to a failure to send responses for signed zones after mishandling an unspecified query. An attacker can exploit this, via a crafted query, to cause a DNSSEC outage, resulting in a denial of service condition.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Upgrade to Unbound version 1.4.4 or later.

Plugin Details

Severity: Medium

ID: 55048

File Name: unbound_1_4_4.nasl

Version: 1.6

Type: remote

Family: DNS

Published: 6/10/2011

Updated: 8/6/2018

Configuration: Enable paranoid mode

Risk Information


Risk Factor: Low

Score: 3.4


Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Vulnerability Information

CPE: cpe:/a:unbound:unbound

Required KB Items: unbound/version, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 4/22/2010

Vulnerability Publication Date: 5/27/2011

Reference Information

CVE: CVE-2009-4008

BID: 48209